The Cocheco River flows for 34 miles in a southeasterly direction and joins with the Salmon Falls River in Dover to form the Piscataqua River. The Cocheco River is located about nine miles northwest of Portsmouth and serves small recreational and fishing vessels.

This project, completed in 1906, consists of a three-mile long channel, seven feet deep and 60-75 feet wide (7.5 feet deep and 50 feet wide in areas where rock was encountered), extending up the Cocheco River from its confluence with the Salmon Falls River to Dover’s Upper Narrows area, located near the town center. The project was built to facilitate shipping, which at that time consisted chiefly of coal and building materials. No commercial navigation has been reported on the river for many years.